Most of catalysts for olefin polymerization are prepared by supporting a titanium halide on an active magnesium chloride. A common method used to prepare the active magnesium chlorides is to react anhydrous MgCl2 with an alcohol to form a magnesium chloride-alcohol adduct of general formula: MgCl2.mROH.nH2O. Then, a titanium halide is supported on such an adduct to afford a solid catalyst component for olefin polymerization. Such alcohol adducts may be prepared by known processes, such as spray drying process, spray cooling process, high-pressure extruding process, or high-speed stirring process. See, for example, U.S. Pat. No. 4,421,674, U.S. Pat. No. 4,469,648, WO8707620, WO9311166, U.S. Pat. No. 5,100,849, U.S. Pat. No. 6,020,279, U.S. Pat. No. 4,399,054, EP0395383, U.S. Pat. No. 6,127,304 and U.S. Pat. No. 6,323,152.
Other magnesium-containing complex carriers useful in the preparation of catalysts for olefin polymerization are also known in the art. For example, CN102040681A discloses a compound that can be used as a carrier of catalysts for olefin polymerization, having a structure of:
wherein R1 is a C1-C12 linear or branched alkyl; R2 and R3 are identical or different, and are independently hydrogen or unsubstituted or halogen-substituted C1-C5 linear or branched alkyl; X's are chlorine or bromine, and one of the X's may be C1-C14 alkyl, C1-C14 alkoxy, C6-C14 aryl or C6-C14 aroxy; m is in a range of from 0.1 to 1.9, n is in a range of from 0.1 to 1.9, and p+m+n=2. Said compound is prepared as follows: MgX2 reacts with an alcohol of general formula RIOH in the presence of an inert dispersion medium at 30 to 160° C., to form a magnesium halide-alcohol adduct solution; then the solution reacts with an oxirane compound at 30 to 160° C., to form the magnesium compound useful as a carrier, wherein X is chlorine or bromine, R1 is a C1-C12 linear or branched alkyl. CN102040680A also discloses an olefin polymerization catalyst, which is prepared by using said compound useful as a carrier of olefin polymerization catalyst disclosed in the above-mentioned patent application.
There is still need a catalyst component for olefin polymerization that exhibits desired properties, such as high activity and high stereo-directing ability, and a method by which such a catalyst component can be simply, effectively, and low-costly prepared.